When a standard magnetic tape of the type used to record seismic exploration or other data has aged about ten (10) years or more, the binder or coating ingredients begin to break down due to exposure to heat and humidity. The coating softens and forms a sticky debris which collects on and contaminates the read/write head and other components of a tape drive machine, and the tape can actually stick to a component ("stiction"). The severity of such stiction depends on the age of the tape and the length of time it was exposed to uncontrolled environments. When copying data from such tape onto a new one, the old tape may experience stiction to the point that a complete read pass is almost impossible, resulting in much wasted time. In severe situations, the tape surface is damaged and seismic data is permanently lost. In any event the tape runs dirty and generates additional debris which causes increased play-back errors.
Various methods have been tried to alleviate the stiction problem, but without any particularly impressive results. One method employs the application of a cleaner, together with special drives and other hardware. However the treated tape must be used quickly, or else it must be treated again. Of course special drive hardware is expensive, and economically justified only when a very larger archive of magnetic tapes requires copying. Another process slows down the input tape speed to a low value, for example 25 inches/sec., with a constant read of the data into a cache and constant write to an output media. However this process is slow, and the data can be lost through read and/or write failures. Yet another process which has been tried is to heat and then super-cool the tape on its drive, while moving at a very short IPS. Still another effort has been to flash freeze the tape. However it is not believed that any of these methods has been met with any degree of commercial success.
A general object of the present invention is to provide new and improved methods and systems for copying data from previously damaged magnetic tape.
Another object of the present invention is to provide new and improved methods and systems of the type described which enables a smooth running, full length copy to be made without sticking and resultant lost time.
Another object of the present invention is to provide new and improved methods and systems of the type described which produce a clean copy with no debris errors.
Still another object of the present invention is to provide new and improved methods and systems of the type described which permits a smooth, clean copy pass so that all available data on the magnetic tape can be properly read.